Purpose: The aims of this study were to develop a simplified, safe, and cost-effective peripheral-blood progenitor-cell (PBPC) mobilization protocol.
Patients and methods: Twenty-six patients with relapsed or resistant lymphomas were entered onto a sequential cohort study in which schedules of various granulocyte colony-stimulating factor (G-CSF) were administered after cyclophosphamide 1.5 g/m2. Hematologic recovery after high-dose carmustine (BCNU) etoposide, cytarabine, and melphalan (BEAM) chemotherapy was compared with that of 46 patients who received autologous bone marrow transplantation (ABMT) without growth factors and 28 patients who received ABMT followed by G-CSF.
Results: When G-CSF (10 micrograms/kg/d) was administered from the day after the cyclophosphamide, neutropenia developed on day 8 followed by an abrupt increase in the WBC count. The optimal time for PBPC harvesting was the day on which the postnadir WBC count was greater than 8.0 x 10(9)/L, as shown by CD34+ cell counts and granulocytic-macrophage colony-forming cell (GM-CFC) assays. The reproducibility of the response was such that routine monitoring of CD34+ cell counts and GM-CFC was not necessary. A single leukapheresis on this day was adequate for prompt hematologic engraftment, and posttransplant G-CSF made little further impact on the rapid recovery. Compared with both control groups, the use of PBPC led to more rapid neutrophil recovery, markedly accelerated platelet recovery, less use of antimicrobial agents and parenteral nutrition, and more than 10 days earlier discharge from hospital. All of these differences were highly significant (P < .01).
Conclusion: A simplified mobilization protocol is described that requires only one apheresis to achieve rapid hematologic engraftment.